How to upgrade win10

Win10 official version will be released this summer, and win10 preview version can be downloaded and used, then win7, win8 system how to upgrade to win10, what is the upgrade method? Microsoft today in a WinHEC 2015 conference session, Microsoft The upgrade path for Windows 10 desktop and mobile is confirmed. The desktop system is mainly updated by ISO image or Windows Update.

It is worth noting that:
Windows 7 and Windows 8/8.1 can be upgraded directly to Windows 10 via ISO image
Windows 7 SP1 and Windows 8.1 S14 can be upgraded directly via Windows Update Windows 10
Others need to upgrade to Windows 7 SP1 or Windows 8.1 S14 first, then upgrade to Windows 10
Windows RT failed to upgrade to Windows 10 or RT 10, Microsoft said it will have special updates to make up for some functions. , but it is not clear what this special update is.
If you are running Windows Vista or XP and are not upgrading directly, you will need a new installation.

It seems that Microsoft's demo documents also confirm that Windows 10 mobile version is also called Windows Mobile 10, and Windows Phone 8.1 can be upgraded to Windows Mobile 10 before it has been confirmed.
In the year of Windows 10 release, users can complete the download and installation and upgrade of genuine Windows 10 through Tencent Computer Manager. Windows XP, Vista, Windows 7, and 8/8.1 users can upgrade with one click. Microsoft announced Windows 7 and 8.1 are available for free upgrade.
Tencent Computer Manager will provide domestic download acceleration, backup, support for one-click restore, rollback, driver installation, program installation, and even customer service to help, it seems that the entire Windows 10 upgrade process has been covered.
However, if you don't like Tencent and 360, you can still upgrade to Windows 10 in an official way.